Can someone please explain/translate what this is all about? Seems like the chamber of the new 105 mm tank gun. Is this a perhaps an electrothermal chemical mechanisme?
I ran the article through an AI. This is what I got:
"This work, titled **"Numerical Simulation of Two-Dimensional Two-Phase Flow of Covered Mixed Propellant for a Certain 105mm High-Pressure Cannon"**, by **Yin, Jihong**, was published in **2021** by **Nanjing University of Science and Technology**.
It is a **Master's thesis** (ie. not necessarily related to a specific tank gun).
The core invention described in this thesis is a **
new type of propellant charge known as "covered mixed propellant" (包覆混合装药)**. This innovative propellant consists of two main components: an **uncovered propellant (未包覆发射药)** and a distinct **covering layer (包覆层)**.
Key characteristics and advantages of this new propellant compared to traditional ones include:
*
The covering layer is not a metallic casing but a **material designed to be consumed during combustion**. It is formed by **adding 30% flame retardant (阻燃剂) to the composition of the uncovered propellant**.
* Both the uncovered propellant and the covering layer have their own determined calorific values, confirming their role in the combustion process.
* The primary purpose of the covering layer is to **control the burning rate of the propellant**.
* **
Advantages over Traditional Propellants:**
* **Improved Control over Combustion:** The covering layer acts as a retardant, allowing for **better control of the propellant's burning speed** [Conversation History, 7].
* **Optimized Pressure Profile:** The covered mixed propellant leads to a different pressure rise phenomenon. It **slows down the rate of pressure increase**, **delays the arrival of the maximum pressure**, and **extends the overall combustion time** within the gun barrel.
* **Plateau Effect in Chamber Pressure:** By carefully mixing the uncovered and covered propellants, it's possible to **achieve a "plateau effect" (膛内压力产生平台效应) in the chamber pressure**, which means fluctuations in pressure can be significantly suppressed, leading to a more stable firing process.
* **Enhanced Energy Utilization:** This combination of propellants helps to **improve the energy utilization rate of the propellant (提高发射药的能量利用率)**.
* **Greater Design Flexibility:** The developed numerical simulation model for this covered mixed propellant provides efficient, safe, and reliable technical support for designing new propellants for cannons, enabling the **optimization of internal ballistic performance**.
* **Projectile Ballistics and Performance (for a 105mm high-pressure cannon):**
The study is specifically conducted for a **105mm high-pressure cannon**, implying the projectiles are of this caliber. While **explicit weight or detailed dimensions of the projectile itself are not provided** in the given excerpts, the thesis extensively analyzes the **muzzle velocity (弹丸初速)** achieved with this new propellant. The muzzle velocity is a key indicator of the projectile's performance.
The **muzzle velocity varies significantly depending on the propellant mixture, the percentage of the covering layer, and the total charge amount:**
* **Influence of Mixing Ratio (Uncovered vs. Covered Propellant):**
* For various mixing ratios, the **muzzle velocities (弹丸初速)** observed range from **1686.948 m/s to 1721.889 m/s**.
* For example, a mixing ratio of 10:0 (all uncovered propellant) yields 1721.889 m/s, while a ratio of 0:10 (all covered propellant) yields 1674.425 m/s. The research also shows that optimizing these ratios can potentially **increase the initial velocity of the projectile**.
* **Influence of Covering Layer Percentage:**
* When the percentage of the covering layer's mass is varied, the muzzle velocities range from **1668.509 m/s (for 15% covering layer) to 1729.549 m/s (for 9% covering layer)**. This suggests an optimal range for the covering layer's proportion to maximize velocity.
* **Influence of Charge Amount (装药量):**
* As the charge amount increases, the **muzzle velocity generally increases**. For instance, with charge amounts ranging from 5.85 kg to 6.05 kg, muzzle velocities are shown to increase from **1678.521 m/s to 1741.075 m/s**.
* **Influence of Ignition Charge Amount (点火药量):**
* Varying the ignition charge amount from 20g to 90g results in muzzle velocities ranging from **1697.859 m/s to 1702.477 m/s**.
* **Influence of Charge Form (药形):**
* Different charge forms (e.g., seven-hole cylindrical vs. nine-hole flower-shaped) also impact muzzle velocity. For example, a "Covered A + main charge" configuration achieved **1561.104 m/s**, while "Covered C + main charge" achieved **1808.973 m/s**.
These findings demonstrate the new propellant's capacity to significantly impact and optimize the projectile's exit velocity from the 105mm cannon."
